Sofa bed hinge



Aug. 24, 1948. M. R. Bolu SOFA BED HINGE Filed Dec. 11. 1944 :inventor:

I, d Qlneg.

Patented Aug. 24, 1948 ingdrawirgg" subject1 to modication; within the f nr in) :sS and back B rest apen: the upper-"fV eff 3 end extends over plate H, and between the spaced legs I and 2 of a staple E which serves as a guide for the latch as well as a stop for limiting the swing of said latch.

I preferably form latch L of a strip of metal bent into a slender but deep U cross section, so as to prevent an accumulation of lint, dirt, etc., which would tend to impair the operation of the latch. At a point L2 near the free end of latch L I provide a trigger L1 (Fig. 5) which is of generally triangular form with the point L4 therefrom extending slightly below the margin L5 and movably disposed within predetermined limits relative to marginal recesses Le formed on the latch and terminating in spaced shoulders L7 and La adapted at times to engage leg 2 of the staple E. Trigger In is formed with edges L and L10 and also relatively angular edges L11 and L12. Edges L0 and L10 engage leg 2 of staple E and portions L11 and L12 engage the web L13 of latch L in order to regulate the operation of the latch and to limit the swing of the trigger.

As shown in Figs. 1, 3 and 4 the latch L is constantly urged into locking engagement with the leg 2 of staple E by means of a spring G which has a central loop or bend G1, and extremity G2 held by a pin or screw G2 and an opposite extremity G1 extending through a perforation in the web of latch L. Thus spring G being anchored at G3 bears against latch L and tends to apply pressure to and for holding the latch in locking engagement with staple E.

Now, referring to Fig. 1, it will be noted that when the sections S and B are disposed to form a seat, pressure or weight applied to either of said sections will tend to lock the hinges against the possibility of folding or adjustment because of the engagement of leg 2 of staple E with shoulder La of the latch, and, under such conditions, leg 2 will be to the left of trigger L2 and either in engagement with or close to the edge L0 of the trigger. Also the trigger is prevented from moving t0 the right (Fig. 1) until there can be a relative movement of the sections B and S, because the edge L12 of the trigger will engage the web L13 and prevent movement of the trigger in a clockwise direction.

When it is desired to arrange the structure as a bed it is necessary to first unlock the latch, it being remembered that as shown in Fig. 1 the leg 2 of staple E is confined in its position between shoulder L of the latch and edge L9 of the trigger La. So, by slightly raising seat S and swinging the seat on its hinge H3 in a counterclockwise direction the leg 2 of the staple moves away from shoulder La and slides over the edge L9 of the trigger as well as over the point L4 of the trigger while the trigger is held with its edge L12 against web L13 of the latch, thereby unlatching and rendering members B and S free to move forwardly together on their hinges C1 and D2 until they finally assume coplanar positions as shown in Fig. 4. During such move ment the trigger is free to retract in a clockwise direction as shown in Fig. and latch L will move forwardly in staple E to its ultimate position shown in Fig. 4, the leg 2 of the staple sliding over the edge L of the trigger and thence rearwardly over edge L5 of the latch. Spring G at all times holds the latch frictionally engaged with leg 2 of the latch. Thus, it is observed that the trigger can not be swung in a counter-clockwise direction on the latch beyond the position established therefor by the engagement of edge L12 with web L13 and serves to lock members B and S in seat position until a movement of seat S disengages the latch from the trigger. Said trigger, therefore serves as a cam over which leg 2 slides when converting the structure from a bed to a seat and vice versa.

When the structure is changed from bed to seat forming positon member B may be raised simultaneously with the rearward sliding of vmember S, during which movement latch L is moved in staple E from the position shown in Fig. 4 to that shown in Fig. 1 and when leg 2 engages portion L4 of the trigger the trigger is forced into the position shown in dotted lines in Fig. 5 and `leg 2 drops into position between shoulder La and edge L2 of the trigger, thereby again locking `the members B and S in seat position. An important feature of my hinge consists in the initial forming of the hinge plates H1 and H2 by means of a single stamping die, so that separate dies for the right and left hand ends of a sofa are not required. However, in order that the plates H1 and H2 may be disposed in a common plane one of the plates, as at H2, may be slightly offset in the vicinity of the pintle H3, as shown in Fig. 1, and the perforations in the plates for hinges D1, L1, G3 and the legs I and 2 of the staple E may be formed in both of said plates at corresponding positions so that said plates may be engageably connected with the bars C and D, latch L, staple E and spring G.

It is apparent that when the structure is latched in seat forming positions the latch L is locked as shown in Fig. 1 with the leg 2 of the staple or keeper E confined between shoulder La and edge L9 of the trigger. Hence pressure on the seat or on the back can not disengage or release the latch. But, if seat S is slightly raised, the latch will be caused to move relative to the keeper to an extent which will cause leg 2 of the keeper to slide over edge L9 and fall to a position between edge L10 and shoulder L0, thereby preventing further movement of members B and S in the direction of each other. Latch L is limited in its upward thrust by leg I of the keeper so that its lower edge will always slide on leg 2 of the keeper. The latch is not necessary to hold the back and seat in their common horizontal plane when arranged for use as a bed but when the structure is converted from a bed to a seat the seat is grasped on its free edge and raised to a point at which the latch will have moved into the latching position of Fig. 1, after which the seat is depressed into horizontal position against the frame A and simultaneously therewith the back is moved into seat position by swinging the structure bodily on pintles C1 and D2 of bars C and D, respectively.

I claim:

1. In a sofa hinge the combination of; pivotally connected seat andback plates, said plates being arranged for connection to seat and back structures respectively to releasably hold the back structure in an erect position above the seat structure; the seat plate having a guide provided with a locking arm; a latch bar of U-shaped cross section pivotally connected at one end to the back plate and extending through the guide of the seat plate; means urging the open edge of the U-shaped latch bar into engagement with the locking arm; a notch forming a pair of spaced shoulders in the open edge of the latch bar; a substantially triangular trigger mechanism on the latch bar adapted to latch and unlatch the bar relative to the arm comprising a trigger pivotally positioned within t'he U-shaped bar, said trigger being pivoted at its base portion with conjoining cam surfaces depending between the shoulders of the latch bar, said base portion having plural stops cooperating with the web of the latch bar to limit the pivotal movement of the trigger; the first of said stops limiting the rearward of the trigger to a position covering the first shoulder of the latch bar and the second stop conning the forward movement of the tris'- ger to a position substantially intermediate the shoulders of the latch bar, the innermost cam surface cooperating with the rst shoulder to place said shoulder into engagement with the locking arm, when the plates are moved in one direction relative to each other, and when said second stop portion engages said latch web, said cam surface contacting the locking arm to guide said first shoulder away from the locking arm when the plates are pivoted relative to each other in the same direction; whereby said locking arm takes a position between said second cam surface and said second shoulder, said last-named cam surface of the trigger, upon pivotal movement of the plates in a reverse direction and engagement of said first stop portion of the trigger with the latch bar, forming a guide for the locking arm away from the second shoulder and over the first shoulder to allow the back structure to assume a coplanar relation with the seat structure.

2. In a sofa hinge as defined in claim 1 wherein the means urging the open edge of the U- shaped latch bar into engagement With the locking arm is in the Vform of a spring.

3. In a sofa hinge the -combination of: pivotally connected seat and back plates, said plates being arranged for connection to seat and back structures respectively to releasably hold the back structure in an erect position above the seat structure; the seat plate having a guide provided with a locking arm; a latch bar pivotally connected at one end to the back plate and extending through the guide of the seat plate; means urging one edge of the latch bar into engagement with the locking arm; a notch forming a pair of spaced shoulders in one edge of the latch bar; a

substantially triangular trigger mechanism on the latch bar adapted to latch and unlatch the bar relative to the arm comprising a trigger pivotaily positioned on the bar, said trigger being pivoted at its base portion with conjoining cam surfaces depending between the shoulders of the latch bar, said base portion having plural stops cooperating with a web on the latch bar to limit the pivotal movement of the trigger; the rst of said stops limiting the rearward movement of the trigger to a position covering the first shoulder of the latch bar and the second stop confining the forward movement of the trigger to a position substantially intermediate the shoulders of the latch bar, the innermost cam surface cooperating with the rst shoulder to place said shoulder into engagement with the locking arm, when the plates are moved in one direction relative to each other, and when said second stop portion engages said latch web, said cam surface contacting the locking arm to guide said irst shoulder away from the locking arm when the plates are pivoted relative to each other in the same direction; whereby said locking arm takes a position between said second cam surfa-ce and said second shoulder, said last-named cam surface of the trigger, upon pivotal movement of the plates in a reverse direction and engagement of said rst stop portion of the trigger with the latch bar, forming a guide for the locking arm away from the second shoulder and over the rst shoulder to allow the back structure to assume a coplanar relation with the seat structure.

MAXIMILIAN REU BOIU.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 833,903 Wagner Oct. 23, 1906 1,140,852 Roeder May 25, 1915 2,224,825 Krakauer et al. Dec. 10, 1940 2,317,105 Neunherz Apr. 20, 1943 2,334,493 Johnson Nov. 16, 1943 2,343,642 Burton Mar. 7, 1944 

